The new network, which will be the seventh largest global design and branding agency with a turnover of pounds 25m, will have offices in Amsterdam, Cape Town, London, Sydney and Johannesburg. It will be known as Brown KSDP.
It will handle existing clients of both networks, some of which overlap, including Coca-Cola and South Africa Breweries (SAB).
Brown ID's client portfolio also includes Unilever, Mattel and Kodak, and KSDP's includes Levi-Strauss Dockers, Mercedes-Benz and Sony.
Brown KSDP will be run with Dave Brown as group chairman, and Peter Hollingsworth as managing director.
Chris Ingram, chairman of Tempus, said: 'KSDP neatly complements our Brown ID business, not only because it extends our geographical coverage, but because it also strengthens our corporate branding expertise.'